Pesticidal compositions containing plant essential oils against mites

ABSTRACT

Pesticidal compositions for the control of mites in stored food products containing one or more plant essential oils. In addition, the present invention is directed to a method for controlling mites from accessing stored food products by applying a pesticidally-effective amount of the above pesticidal compositions to a locus where pest control is desired.

CROSS REFERENCE TO RELATED APPLICATION

This is a Divisional of U.S. patent application Ser. No. 09/604,083,filed Jun. 27, 2000.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/140,844, filed Jun. 28, 1999, the entire disclosure of which isincorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates, in general, to pesticidal compositionscontaining plant essential oils and/or derivatives thereof againstmites. In one aspect, the present invention relates to pesticidalcompositions containing one or more plant essential oils and/orderivatives thereof to be used as a contact pesticide in containers orcartons where food products are stored. In another aspect, the presentinvention relates to pesticidal compositions containing one or moreplant essential oils and/or derivatives thereof to be used as a fumigantpesticide in containers or cartons where food products are stored. In afurther aspect, the present invention relates to a method forcontrolling stored product pests by the application of pesticidallyeffective amounts of the pesticidal compositions to the container orcarton in which food products are stored.

BACKGROUND OF THE INVENTION

Pests (invertebrates, insects, arachnids, larvae thereof, etc.) areannoying to humans for a myriad of reasons. They have annually costhumans billions of dollars in crop losses and in the expense of keepingthem under control. For example, the losses caused by pests inagricultural environments include decreased crop yield, reduced cropquality, and increased harvesting costs.

Over the years, synthetic chemical pesticides have provided an effectivemeans of pest control. For example, one approach teaches the use ofcomplex, organic insecticides, such as disclosed in U.S. Pat. Nos.4,376,784 and 4,308,279. Other approaches employ absorbent organicpolymers for widespread dehydration of the insects. See, U.S. Pat. Nos.4,985,251; 4,983,390; 4,818,534; and 4,983,389. Use of inorganic saltsas components of pesticides has also been tried, as disclosed in U.S.Pat. Nos. 2,423,284 and 4,948,013, European Patent Application No. 462347, Chemical Abstracts 119(5):43357q (1993) and Farm ChemicalsHandbook, page c102 (1987).

However, it has become increasingly apparent that the widespread use ofsynthetic chemical pesticides has caused detrimental environmentaleffects that are harmful to humans and other animals. For instance, thepublic has become concerned about the amount of residual chemicals thatpersist in food, ground water and the environment, and that are toxic,carcinogenic or otherwise incompatible to humans, domestic animalsand/or fish. Moreover, some target pests have even shown an ability todevelop immunity to many commonly used synthetic chemical pesticides. Inrecent times, regulatory guidelines have encouraged a search forpotentially less dangerous pesticidal compositions via stringentrestrictions on the use of certain synthetic pesticides. As a result,elimination of effective pesticides from the market has limitedeconomical and effective options for controlling pests. As analternative, botanical pesticides are of great interest because they arenatural pesticides, i.e., toxicants derived from plants that are safe tohumans and the environment.

With respect to protecting stored food products from insects, thissafety issue is even more important. Some of the major stored foodproducts affected by mites include, but are not limited to, flour,grain, wheat, barley, corn, pasta, cereal, pet food, and others. Sincethe pesticides will come in contact with the stored food products tosome extent, it is essential that the pesticides be safe for mammals anddo not persist for very long, but rather break down very easily. Storedfood products have long been suspect to mites, including mold mites,cheese mites, grain mites, and clover mites, which contaminatefoodstuffs, sometimes making it unfit for consumption, causing certainreactions in mammals that may result in terrible discomfort, and ingeneral can prove to be a terrible nuisance.

Mites can access stored food products in one of two ways. First, themites may be in the food which is processed and packaged, then lay eggsand create problems as discussed above. Secondly, the mites maypenetrate the package after the stored food products have beenprocessed, by literally eating their way into the containers or cartons.

Accordingly, there is a great need for novel pesticidal compositions,containing no pyrethrum, synthetic pyrethroids, chlorinatedhydrocarbons, organo phosphates, carbamates and the like, to be usedinside the containers or cartons for stored food products as both acontact and fumigant pesticide against mites. In addition, there is aneed for a method of treating the containers or cartons to kill andrepel mites, thereby preserving the stored food products inside.

SUMMARY OF THE INVENTION

A primary object of the present invention is to provide novel pesticidalcompositions for containers or cartons in which food products arestored.

Another object of the invention is to provide novel pesticidalcompositions containing one or more plant essential oils and/orderivatives thereof, natural or synthetic, as a contact pesticide incontainers or cartons against mites.

A further object of the present invention is to provide novel pesticidalcompositions that contain one or more plant essential oils and/orderivatives thereof, natural or synthetic, as a fumigant pesticide incontainers or cartons against mites.

It is also an object of the present invention to provide a method oftreating the containers or cartons of stored food products to kill andrepel mites.

It is also an object of the present invention to provide a pesticidalcomposition and method for mechanically, physiologically and/or neurallycontrolling mites.

It is a further object to provide a safe, non-toxic pesticidalcomposition and method that will not harm mammals or the environment.

It is still another object to provide a pesticidal composition andmethod that has a pleasant scent or is unscented, and that can beapplied without burdensome safety precautions.

It is still another object to provide a pesticidal composition andmethod as described above which can be inexpensively produced oremployed.

It is yet another object of the invention to provide a pesticidalcomposition and method to which pests cannot build immunity and/orresistance.

The above and other objects are accomplished by the present inventionwhich is directed to pesticidal compositions comprising plant essentialoils and/or derivatives thereof, natural or synthetic, in admixture withsuitable carriers. In addition, the present invention is directed to amethod for controlling mites by applying a pesticidally-effective amountof the above pesticidal compositions to the container or carton in whichfood products are stored.

Additional objects and attendant advantages of the present inventionwill be set forth, in part, in the description that follows, or may belearned from practicing or using the present invention. The objects andadvantages may be realized and attained by means of theinstrumentalities and combinations particularly recited in the appendedclaims. It is to be understood that the foregoing general descriptionand the following detailed description are exemplary and explanatoryonly and are not to be viewed as being restrictive of the invention, asclaimed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

All patents, patent applications and literatures cited in thisdescription are incorporated herein by reference in their entirety. Inthe case of inconsistencies, the present disclosure, includingdefinitions, will prevail.

In one embodiment, the present invention provides a pesticidalcomposition comprising, in admixture with a suitable carrier andoptionally with a suitable surface active agent, comprising one or moreplant essential oil compounds and derivatives thereof, natural orsyntetic, including racemic mixtures, enantiomers, diastereomers,hydrates, salts, solvates and metabolites, etc.

Each plant essential oil or derivative thereof, comprises a monocyclic,carbocyclic ring structure having six-members and substituted by atleast one oxygenated or hydroxyl functional moiety. Examples of plantessential oils encompassed within the present invention, include, butare not limited to, members selected from the group consisting ofaldehyde C16 (pure), α-terpineol, amyl cinnamic aldehyde, amylsalicylate, anisic aldehyde, benzyl alcohol, benzyl acetate,cinnamaldehyde, cinnamic alcohol, carvacrol, carveol, citral,citronellal, citronellol, p-cymene, diethyl phthalate, dimethylsalicylate, dipropylene glycol, eucalyptol (cineole), eugenol,iso-eugenol, galaxolide, geraniol, guaiacol, ionone, menthol, methylanthranilate, methyl ionone, methyl salicylate, α-phellandrene,pennyroyal oil, perillaldehyde, 1- or 2-phenyl ethyl alcohol, 1- or2-phenyl ethyl propionate, piperonal, piperonyl acetate, piperonylalcohol, D-pulegone, terpinen-4-ol, terpinyl acetate, 4-tertbutylcyclohexyl acetate, thyme oil, thymol, metabolites oftrans-anethole, vanillin, ethyl vanillin, and the like. As these plantessential oil compounds are known and used for other uses, they may beprepared by a skilled artisan by employing known methods.

For example, in a preferred embodiment, the present invention isdirected to a pesticidal composition for controlling mites comprising aplant essential oil selected from the group consisting of 2-phenyl ethylalcohol, 2-phenyl ethyl propionate, benzyl alcohol, and trans-anethole,or a combination of same, with a suitable release agent. Data belowshows that this embodiment is highly effective, i.e. exhibited goodcontrol against mold mites in food cartons.

It will be appreciated by the skilled artisan that the pesticidalcompositions of the present invention unexpectedly exhibit excellentpesticidal activities using one or more U.S. F.D.A. approved plantessential oils, in lieu of conventional pesticides which are not safefor use in food containers or cartons. Without wishing to be bound bythe following theories, it is believed that plant essential oilsantagonize a pest's nerve receptors or may act as Phase I and/or PhaseII drug metabolizing enzyme inhibitors. Alternatively, plant essentialoils may act via an alternative mode of action. The plant essential oilsmay act as agonists or antagonists against the octopamine receptors thatare distinct to invertebrates. In any event, the net effect of thetoxicity and action of the inventive composition disclosed herein isheretofore unknown and unexpected.

Use of pesticidal compositions of the present invention generallyresults in 100% mortality on contact, and provides equivalent fumigantaction for extended periods of time. As such, they are advantageouslyemployed as pesticidal agents in uses such as, without limitation,containers and cartons for stored food products such as flour, grain,wheat, barley, corn, pasta, cereal, pet food, and others.

The pesticidal compositions herein are so chemically inert that they arecompatible with substantially any other constituents of stored foodproducts, and they may be used safely in the either the preparation offood products, or the application to the container or carton afterprocessing and/or packaging of the food products.

The term “carrier” as used herein means an inert or fluid material,which may be inorganic or organic and of synthetic or natural origin,with which the active compound is mixed or formulated to facilitate itsapplication to the container or carton or other object to be treated, orits storage, transport and/or handling. In general, any of the materialscustomarily employed in formulating pesticides, herbicides, orfungicides, are suitable. The inventive pesticidal compositions of thepresent invention may be employed alone or in the form of mixtures withsuch solid and/or liquid dispersible carrier vehicles and/or other knowncompatible active agents such as other pesticides, or acaricides,nematicides, fungicides, bactericides, rodenticides, herbicides,fertilizers, growth-regulating agents, etc., if desired, or in the formof particular dosage preparations for specific application madetherefrom, such as solutions, emulsions, suspensions, powders, pastes,and granules which are thus ready for use. The pesticidal compositionsof the present invention can be formulated or mixed with, if desired,conventional inert pesticide diluents or extenders of the type usable inconventional pesticide formulations or compositions, e.g. conventionalpesticide dispersible carrier vehicles such as gases, solutions,emulsions, suspensions, emulsifiable concentrates, spray powders,pastes, soluble powders, dusting agents, granules, foams, pastes,tablets, aerosols, natural and synthetic materials impregnated withactive compounds, microcapsules, coating compositions for use on seeds,and formulations used with burning equipment, such as fumigatingcartridges, fumigating cans and fumigating coils, as well as ULV coldmist and warm mist formulations, etc.

Formulations containing the pesticidal compositions of the presentinvention may be prepared in any known manner, for instance by extendingthe pesticidal compositions with conventional pesticide dispersibleliquid diluent carriers and/or dispersible solid carriers optionallywith the use of carrier vehicle assistants, e.g. conventional pesticidesurface-active agents, including emulsifying agents and/or dispersingagents, whereby, for example, in the case where water is used asdiluent, organic solvents may be added as auxiliary solvents. Suitableliquid diluents or carriers include water, petroleum distillates, orother liquid carriers with or without surface active agents. The choiceof dispersing and emulsifying agents and the amount employed is dictatedby the nature of the composition and the ability of the agent tofacilitate the dispersion of the pesticidal compositions of the presentinvention. Non-ionic, anionic, amphoteric, or cationic dispersing andemulsifying agents may be employed, for example, the condensationproducts of alkylene oxides with phenol and organic acids, alkyl arylsulfonates, complex ether alcohols, quaternary ammonium compounds, andthe like.

Liquid concentrates may be prepared by dissolving a composition of thepresent invention with a solvent and dispersing the pesticidalcompositions of the present inventions in water with the acid ofsuitable surface active emulsifying and dispersing agents. Examples ofconventional carrier vehicles for this purpose include, but are notlimited to, aerosol propellants which are gaseous at normal temperaturesand pressures, such as Freon; inert dispersible liquid diluent carriers,including inert organic solvents, such as aromatic hydrocarbons (e.g.benzene, toluene, xylene, alkyl naphthalenes, etc.), halogenatedespecially chlorinated, aromatic hydrocarbons (e.g. chloro-benzenes,etc.), cycloalkanes, (e.g. cyclohexane, etc.). paraffins (e.g. petroleumor mineral oil fractions), chlorinated aliphatic hydrocarbons (e.g.methylene chloride, chloroethylenes, etc.), alcohols (e.g. methanol,ethanol, propanol, butanol, glycol, etc.) as well as ethers and estersthereof (e.g. glycol monomethyl ether, etc.), amines (e.g. ethanolamine,etc.), amides (e.g. dimethyl formamide etc.) sulfoxides (e.g. dimethylsulfoxide, etc.), acetonitrile, ketones (e.g. acetone, methyl ethylketone, methyl isobutyl ketone, cyclohexanone, etc.), and/or water; aswell as inert dispersible finely divided solid carriers such as groundnatural minerals (e.g. kaolins, clays, vermiculite, alumina, silica,chalk, i.e. calcium carbonate, talc, attapulgite, montmorillonite,kieselguhr, etc.) and ground synthetic minerals (e.g. highly dispersedsilicic acid, silicates, e.g. alkali silicates, etc.).

Surface-active agents, i.e., conventional carrier vehicle assistants,that may be employed with the present invention include, withoutlimitation, emulsifying agents, such as non-ionic and/or anionicemulsifying agents (e.g. polyethylene oxide esters of fatty acids,polyethylene oxide ethers of fatty alcohols, alkyl sulfates, alkylsulfonates, aryl sulfonates, albumin hydrolyzates, etc. and especiallyalkyl arylpolyglycol ethers, magnesium stearate, sodium oleate, etc.);and/or dispersing agents such as lignin, sulfite waste liquors, methylcellulose, etc.

In the preparation of wettable powders, dust or granulated formulations,the active ingredient is dispersed in and on an appropriately dividedcarrier. In the formulation of the wettable powders the aforementioneddispersing agents as well as lignosulfonates can be included. Dusts areadmixtures of the compositions with finely divided solids such as talc,attapulgite clay, kieselguhr, pyrophyllite, chalk, diatomaceous earth,vermiculite, calcium phosphates, calcium and magnesium carbonates,sulfur, flours, and other organic and inorganic solids which actscarriers for the pesticide. These finely divided solids preferably havean average particle size of less than about 50 microns. A typical dustformulation useful for controlling insects contains 1 part of pesticidalcomposition and 99 parts of diatomaceous earth or vermiculite. Granulesmay comprise porous or nonporous particles. The granule particles arerelatively large, a diameter of about 400-2500 microns typically. Theparticles are either impregnated or coated with the inventive pesticidalcompositions from solution. Granules generally contain 0.05-15%,preferably 0.5-5%, active ingredient as the pesticidally-effectiveamount. Thus, the contemplated are formulations with solid carriers ordiluents such as bentonite, fullers earth, ground natural minerals, suchas kaolins, clays, talc, chalk, quartz, attapulgite, montmorillonite ordiatomaceous earth, vermiculite, and ground synthetic minerals, such ashighly-dispersed silicic acid, alumina and silicates, crushed andfractionated natural rocks such as calcite, marble, pumice, sepioliteand dolomite, as well as synthetic granules of inorganic and organicmeals, and granules of organic materials such as sawdust, coconutshells, corn cobs and tobacco stalks. Adhesives, such as carboxymethylcellulose, natural and synthetic polymers, (such as gum arabic,polyvinyl alcohol and polyvinyl acetate), and the like, may also be usedin the formulations in the form of powders, granules or emulsifiableconcentrations.

If desired, colorants such as inorganic pigments, for example, ironoxide, titanium oxide and Prussian Blue, and organic dyestuffs, such asalizarin dyestuffs, azo dyestuffs or metal phthalocyanine dyestuffs, andtrace elements, such as salts of iron, manganese, boron, copper, cobalt,molybdenum and zinc may be used.

In commercial applications, the present invention encompasses carriercomposition mixtures in which the pesticidal compositions are present inan amount substantially between about 0.01-95% by weight, and preferably0.5-90% by weight, of the mixture, whereas carrier composition mixturessuitable for direct application or field application generallycontemplate those in which the active compound is present in an amountsubstantially between about 0.0001-10%, preferably 0.01-1%, by weight ofthe mixture. Thus, the present invention contemplates over-allformulations that comprise mixtures of a conventional dispersiblecarrier vehicle such as (1) a dispersible inert finely divided carriersolid, and/or (2) a dispersible carrier liquid such as an inert organicsolvent and/or water, preferably including a surface-active effectiveamount of a carrier vehicle assistant, e.g. a surface-active agent, suchas an emulsifying agent and/or a dispersing agent, and an amount of theactive compound which is effective for the purpose in question and whichis generally between about 0.0001-95%, and preferably 0.01-95%, byweight of the mixture.

The pesticidal compositions can also be used in accordance withso-called ultra-low-volume process, i.e. by applying such compounds orby applying a liquid composition containing the same, via very effectiveatomizing equipment, in finely divided form, e.g. average particlediameter of from 50-100 microns, or even less, i.e. mist form, forexample by airplane crop spraying techniques. In this process it ispossible to use highly concentrated liquid compositions with said liquidcarrier vehicles containing from about 20 to 95% by weight of thepesticidal compositions or even the 100% active substances alone, e.g.about 20-100% by weight of the pesticidal compositions. Theconcentration in the liquid concentrate will usually vary from about 10to 95 percent by weight and in the solid formulations from about 0.5 to90 percent by weight.

Furthermore, the present invention encompasses methods for killing,combating or controlling pests, which comprises applying to at least oneof correspondingly (a) such pests and (b) the corresponding habitatthereof, i.e. the locus to be protected, e.g. to a container or cartonfor stored food products, a correspondingly combative, a pesticidallyeffective amount, or toxic amount of the particular pesticidalcompositions of the invention alone or together with a carrier as notedabove. The instant formulations or compositions may be applied in anysuitable usual manner, for instance by spraying, atomizing, vaporizing,scattering, dusting, watering, squirting, sprinkling, pouring,fumigating, and the like. The method for controlling mites comprisesapplying the inventive composition, ordinarily in a formulation of oneof the aforementioned types, to a locus or area to be protected from theinsects, such as the food containers or cartons. The compound, ofcourse, is applied in an amount sufficient to effect the desired action.This dosage is dependent upon many factors, including the targeted pest,the carrier employed, the method and conditions of the application,whether the formulation is present at the locus in the form of anaerosol, or as a film, or as discrete particles, the thickness of filmor size of particles, and the like. Proper consideration and resolutionof these factors to provide the necessary dosage of the active compoundat the locus to be protected are within the skill of those versed in theart. In general, however, the effective dosage of the compound of thisinvention at the locus to be protected—i.e., the dosage with which thepest comes in contact—is of the order of 0.001 to 5.0% based on thetotal weight of the formulation, though under some circumstances theeffective concentration will be as little as 0.0001% or as much as 20%,on the same basis.

The pesticidal compositions and methods of the present invention areeffective against a wide variety of mites and it will be understood thatthe mites exemplified and evaluated in the working Examples herein isrepresentative of such a wider variety. For instance, the presentinvention can be used to control mites that attack plants orwarm-blooded animals, stored products and fabrics. Representative storedproducts that can be protected from pest attack by the present inventioninclude, without limitation, grains, flour and flour products, tobaccoand tobacco products, processed foods, cereals and the like.Representative fabrics that can be protected from pest attack by theinvention are wool, cotton, silk, linen and the like.

The composition and method of the present invention will be furtherillustrated in the following, non-limiting Examples. The Examples areillustrative of various embodiments only and do not limit the claimedinvention regarding the materials, conditions, weight ratios, processparameters and the like recited herein.

EXAMPLE 1 Pesticidal Effects of Plant Essential Oils in Food Cartonsagainst the Mold Mite

Various plant essential oils were successfully screened for contacttoxicity against the mold mite These plant essential oils were thenevaluated in food cartons for toxicity against mold mites. Half pintmilk cartons were used as sample food containers. The composition of thecarton is multilayer paper, plastic and foil. The last two inner layersare foil and plastic; the food inside the carton is in contact with theplastic. Utilizing a ULV sprayer, the plant essential oils were foggedinto the container. Approximately one gram of liquid test substance(i.e. plant essential oil) was deposited into the container. The desiredamount of food and approximately 100 mites per carton were then added tothe container and the carton was sealed. The materials tested included2-phenyl ethyl alcohol, 2-phenyl ethyl propionate, trans-anethole, andbenzyl alcohol. The cartons were opened at 24 hour intervals, a newcarton each interval, to observe for pest mortality and the results wererecorded.

2-phenyl ethyl alcohol and 2-phenyl ethyl propionate gave good controlof the mites from day one, and all samples tested gave good controlafter day four.

The experiment was repeated, but the cartons were not opened until dayten. The results were the same as the previous study. All samples gavegood control, but 2-phenyl ethyl alcohol and 2-phenyl ethyl propionateprovided the best results of mortality.

This data clearly demonstrates that plant essential oils may be used asa safe and effective alternative pesticide for control of mites incontainers and/or cartons for stored food products.

As can be seen from the above discussion, the pesticidal combinations ofactive compounds according to the present invention are markedlysuperior to known pesticidal agents/active compounds conventionally usedfor pest control in stored food product containers and/or cartons.

Although illustrative embodiments of the invention have been describedin detail, it is to be understood that the present invention is notlimited to those precise embodiments, and that various changes andmodifications can be effected therein by one skilled in the art withoutdeparting from the scope and spirit of the invention as defined by theappended claims.

What is claimed is:
 1. A method for controlling mold mites comprising:applying to a locus where control is desired a pesticidally-effectiveamount a composition comprising 2-phenyl ethyl propionate and anacceptable carrier.
 2. A method for controlling mold mites comprising:applying to a locus where control is desired a pesticidally-effectiveamount a composition comprising trans-anethole and an acceptablecarrier.